Method of making piano-hammers



I. WROZINA.

METHOD OF MAKING PIANO HAM-MERS.

' APPLICATION FILED AUG-2| 1920.

Patented Apr. 19, 1921.

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IGNATIUS WROZTNA, 0F BRIDGEIEORT, CONNECTICUT, ASSIGNOB, OF ONE-THIRD'JlO OTTO J. DIEHL AND ONE-THIRD '10 MARTIN A.

CONNECTICUT.

HEAJNUE, BOTH OE BEIDGEPOM,

METHOD OF MAKING EIANO-HAMMERS.

Specification of Letters Patent.

Patented Apr. is, 1921.

Application filed August 2, 1920. Serial No. 400,770.

To all whom it may concern.

B it known that I, IGNATIUS VVROZINA, a subject of Austria, and residingat the city of Bridgeport, in the countyof F airfield,

and State of Connecticut, U. S. A., have invented certain new and usefulImprovements in Methods of Making Piano-Hammers; and I do declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

This invention relates to certain new and useful improvements in amethod of making piano hammers whereby the felt faces of the hammers maynot only be expeditiously and easily toned but also may be thoroughlyand properly toned.

Heretofore, it has been the practice to assemble the hammers within aceive the felt facing in a continuous strip subsequent to which the feltwas cut so as to provide each individual hammer with a felt face Thehammers were then toned twice, first, by the bench toner, who would tonethem in the rough by forcing the usual toning needles into the strikingface of the felt, and secondly, by an expert afterthe hammers had beenassembled within' a piano. This method was very tedious and requiredconsiderable skill on the part of'the toner who had to exercise thegreatest care so as not to fray the edges of the felt. The edges wouldbecome ragged and ravelly ners if the needles penetrated the felt at thecorners, and thus render an imperfect toning and the tone when strikingthe piano string would not be of the ropef timber and mellowness.Moreover, both the bench and expert toning were necessarily onlysuperficial, that is to say, the toning needles penetrated the felt buta short distance, because of the fear that a deep penetration of thefelt near the angular edges would break 'or fray the felt and cause aharsh tone. This would also be the result when the edges of the feltwere broken and frayed by striking the same with the toning needles.

It is, therefore, the principal object of this invention to overcome andobviat the above difiiculties and imperfections, and the" inventionconsists in the steps and sequence of steps hereinafter described andclaimed, reference being had to the accompanying drawing wherein:

at the cornose, the thinner Figure 1 shows the several piano hammersclamped within What is termed a tray,v in the piano art:

Fig. 2 is a View disclosing the hammers with the continuous or integralfelt facing strip aflixed thereto rior to cutting the same up intoindividual fdlted hammers, and also showing the active face portion ofthe continuousfelt strip toned by penetrating the same w1t h the usualtoning needles:

F Fig. 3 1s avertical section on line .3-3 of Fig. 4 is a fragmentaryplan view of the felt strip per se: and Y Fig. 5 is a transverse sectionon line 55 ofFig. 4.

My improved process follows the initial steps of assembling the woodenbacks 1 of the hammers within the tray 2, where they are securely andfirmly clamped by the bolts 3 with the top edges flush, and the integralfelt strlp 4 .is then aflixed to the face portions of the assembledhammers. Owing to the fact that the hammers for the lower tones areshorter a filler block or strip 5 is inserted therebeneath in the tray.The in- .yentlon consists in toning the felt strip while in itscontinuous or integral state and prior to severing the assembled feltedhammers into the individual hammers. To this end the strip is toned bypenetrating the striking area throughout its len h, as indicated in Fig.3, subsequent to whlch the hammers are divided or separated by cuttingthrough wooden backs 1 and carried through the felt to separate theindividual hammers, when the. edges will be found intact with noraggedness or raveling.

The felt strip, which is .used to face the hammers, is triangular incross section and tapers lengthwise thereby varying in thickportionfacing the hammers used for the higher tones and the thicker ortionfacing those for the lower tones. n practice this felt stri is placedover a female'die with the angu ar portion of the strip uppermost, andthe tray with the assembled hammers is used as the male die, the hammerbodies, extending directly against the angular part ofthe felt strip.The tray is then subjected sure to drive the felt down within the fetoenormous presthe hammers whic dividing the same.

' the bench and expert toning,

The individual toning of the hammers is thus obviated and replaced bythe far less tedious and more expeditious step of toning the strip whilein its entirety.

This improved method eliminates both and also gives a far better tonlng.Moreover, no subsequent toning'is necessary because the toning needlespenetrate clear through the felt body, and the toning is effectedthroughout the entire striking faces of the hammers, which ispractically possible to accomplish under the former practice.

Also, by the-old method the felt fre-- quently separated from the sidesof the hammer bodies for two reasons first, be-

' cause the felt is bent against its greatest resistance around the'hammer bodies and therefore the glue is often insuflicient to resist'the resilient tendency of the felt, and second, because the penetrationof the felt by the tonin' needles always relieves this resilient tenency, but the needles do not penetrate deepenough to afford completerelief. By the present method the needles penetrate the entire body ofthe felt and therefore there is efiected a complete relaxation "of thisresilient tendency and the felt body adheres absolutely to the woodenhammer body.

What is claimed is:

1. The method of making piano hammers,

consisting in assembling the hammer bodies within a holder, affixing acontinuous strip of felt facing to the hammer bodies, toning the entirestriking area of the strip by penetrating the same with toning needles,and then separating the hammer bodies and the strip into individualhammers.

2. The method of making piano hammers, consisting in first applying acontinuous stri of felt to thefaces of the hammer bodies, and thentoning the continuous felt facing strip prior to separating the sameinto individual strikin faces.

3. The method of malliing piano hammers, consisting in toning thecontinuous felt facing strip after the same has been affixed to aplurality of assembled hammer bodies and before the whole has beenseparated into.

whereof I afiix my signature.

